OUR PROCESS
COOPERING & MATURATION
HAMMER AND TONGS - INSIDE THE COOPERAGE
The new spirit is reduced to around 63% alcohol with natural spring water from our Robbie Dhu springs and then filled into hand-built oak casks, prepared and maintained at the Distillery's own cooperage. All casks filled at The Glenfiddich Distillery are first checked by one of our qualified coopers, a practice unique to the making of Glenfiddich whiskies.
The coopers, who apprentice for approximately five years (as much as a doctor!), work with incredible speed and agility to assemble, repair or reconstruct around 25 casks each every day. We use only the very best casks made from the very best wood, such as sherry butts from Spain and bourbon barrels from America that have had only one filling of sherry or bourbon whisky.
By using these ‘second-hand’, high quality casks, we achieve a high quality spirit. Mellowed by previous use, the oak helps mature the Scotch whisky, allowing it to breathe, soften, assume subtle flavours and absorb a pale golden colour. Sometimes we char the inside of the cask with a blast of fire to open the grain of the wood, allowing the Scotch whisky to interact more easily with it.
We know that the quality of our barrels is vital, as this is where the magic happens. Even when pressure-testing our sherry barrels, we use sherry instead of water so that their integrity is not compromised.
MATURATION - WHERE THE MAGIC HAPPENS
Our distillery is the only single malt whisky still using wooden marrying tuns (2,000 litre plus vats). We also marry our whiskies for an unusually long period of time…
These wooden casks are then stored on-site in our traditional warehouses, and the spirit is left to mature. The atmospherically dark, damp interior of the warehouse and the temperature, humidity and climate of this environment provide optimum conditions for maturing the best quality Scotch whiskies. It is here that the Glenfiddich spirit acquires its distinctive, well-balanced character.
As a cask ages and develops, it breathes in the pure Highland air through the porous oak. Consequently, alcohol compounds evaporate off the whisky, through the wood, back into the air - roughly 2% from each cask per year. It is estimated that throughout Scotland, approximately 16 million litres of Scotch whisky is lost this way each year. This lost spirit is known as “the Angels' Share”.